Thrombus removal and intravascular distal embolic protection device

ABSTRACT

A clot extraction catheter comprises a tubular mesh, a tapered tip fixed to the tubular mesh distal end, a rim attached to the tubular mesh proximal end, control wires, a guidewire channel, an inner sheath, and an outer sheath advancable over the guidewire channel and inner sheath. To extract a clot, the catheter is advanced through the clot over a guidewire. The inner sheath is retracted relative to the control wires and the tubular mesh, allowing the rim and the tubular mesh to expand. The tubular mesh is retracted to capture the clot, constrained proximally by the distal portion of the inner sheath, and retracted with the inner sheath into the outer sheath. The control wires may be manipulated to control the angle of the rim relative to the longitudinal axis of the sheaths, facilitating clot capture and retraction of the tubular mesh into the sheaths thereafter.

CROSS-REFERENCE

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/289,027, filed May 28, 2014, which claims the benefit ofU.S. Provisional Application No. 61/828,264, filed May 29, 2013, thefull disclosures of which are incorporated herein by reference.

BACKGROUND

The present disclosure generally relates to medical devices, systems,and methods. In particular, the present disclosure generally relates tothe removal of intravascular or intracavitary thrombus or other materialwhich may frequently require removal to restore blood flow or othernormal functionality of the organ system affected.

Typically, blood clot or emboli to the pulmonary arteries of the lung,the brain, the peripheral arteries of the extremities, in the venoussystem, or in dialysis access vessels are potentially life and/or limbthreatening conditions. These clots are typically cleared when medicallyindicated by either pharmacological (thrombolytic and/or anticoagulantdrugs) or mechanical means or a combination of the two. Thrombolyticdrugs typically require several hours to days to accomplish dissolvingthese clots. Frequently, there is not sufficient “warm” ischemic timefor the target organ to permit such a long time to reperfusion.Thrombolytic drugs also have an approximately 5% incidence of majorcomplications such as hemorrhage and stroke. Currently availablemechanical devices may not be effective in the presence of large volumesof thrombus or may have a very large diameter and may be stiff. Thus,these devices may be difficult or impossible to advance into curved andtortuous vessels such as the pulmonary arteries. The “Hydrolyzer”devices available in the marketplace may break up a clot and suction theresulting particles out, but may infuse large volumes of fluid as partof their action. Such infusion may be physiologically difficult tohandle for the patient. Other devices, like “AngioVac” may require aminiature veno-venous cardiovascular bypass to allow filtering out ofthe suctioned thrombus and return of the cleared blood to the patient.Most of these devices may also hemolyze blood, which may result indamage to the kidneys and may also cause distal emboli.

For these reasons, emergency open surgical thrombectomy, which in itselfmay have a high mortality and morbidity, is often employed as a lastresort, especially for large pulmonary emboli. There are therefore needsfor devices which can rapidly and safely extract large volumes of bloodclot or other materials with little or no adjuvant use of thrombolyticdrugs. Such devices may be used during intravascular interventions toprevent distal embolization by capture of blood clots or atheromatousmaterial.

References which may be of interest include U.S. Pat. Nos. 8,377,092,7,479,153, 6,494,895, and 7,976,560 and U.S. Patent ApplicationPublication Nos. 2012/0330350 and 2012/0330346.

SUMMARY

The present disclosure provides medical devices, systems, and methodsfor the removal of intravascular or intracavitary thrombus or othermaterial.

Aspects of the present disclosure provide clot extraction catheters. Aclot extraction catheter may comprise an expandable tubular mesh, atapered tip, a self-expanding rim, at least three control wires, and aninner sheath. The expandable tubular mesh may have a distal end and aproximal end. The expandable tubular mesh may have an expandedconfiguration and a constrained configuration. The tapered tip may befixed to the distal end of the expandable tubular mesh. Theself-expanding rim may be attached to the proximal end of the expandabletubular mesh. The self-expanding rim may have an unconstrained diameterwhich is greater than a width of the proximal end of the tapered tip.The control wires may be attached to the self-expanding rim. The innersheath may be advancable over the control wires to constrain at least aportion of the self-expanding rim and at least a portion of the tubularmesh within a lumen of the inner sheath. The control wires can bemanipulated to control the angle of the self-expanding rim relative tothe longitudinal axis of the inner sheath when the self-expanding rim isunconstrained. The self-expanding rim may be advanced past a clot,expanded, and finally retracted to capture the clot within theexpandable tubular mesh. The clot extraction catheter may furthercomprise an outer sheath advancable over the inner sheath.

In some embodiments, an expandable element may be provided to facilitateclot capture in conjunction with the self-expanding rim. The expandableelement, typically an inflatable balloon, may be mounted on a distal endof the inner sheath, on a separate pusher tube, or on a control wiresheath further described below. The pusher sheath may be axiallytranslated to advance and retract the expandable element. The pushersheath may be disposed within the outer sheath and possibly even withinthe inner sheath. Retraction of the self-expanding rim may push the clotagainst the expanded expandable element to urge the clot into theexpandable tubular mesh. Alternatively or in combination, the expandableelement may be advanced to push the clot into the expandable tubularmesh.

Referring back to the other components of the clot extraction catheter,the proximal end of the tapered tip may have a rounded lip to reduceinterference as the catheter is drawn proximally through a bodily lumenor cavity.

The control wires may comprise a main wire and two chord wires. The mainwire may be translatable proximally and distally. The two chord wiresmay be translatable proximally and distally independently from theprimary wire. The wires may be independently translated proximallyand/or distally to control the angle of the self-expanding rim relativeto the axis of the inner sheath when the self-expanding rim isunconstrained. The two chord wires may comprise a first chord wire and asecond chord wire each independently translatable proximally anddistally. In some embodiments, the main control wire may be fixed andthe two chord wires may be independently translatable proximally anddistally. The control wires may also be used to rotate the clotextraction catheter to adjust its orientation within a bodily vessel orcavity. The control wires may be attached to the rim directly or one ormore of the control wires may be coupled to a nipple or protrusion fromthe rim. In some embodiments, the control wires may each compriseproximal portions which are fixed to one another.

The control wires may be retracted proximally to capture a clot orthrombus once the self-expanding rim and expandable tubular mesh isadvanced and positioned distally of the clot or thrombus. The expandabletubular mesh, once capturing the blood clot, may be closed by advancingthe inner sheath over the control wires and at least a portion of theexpandable tubular mesh. Alternatively or in combination, the innersheath may be advanced over the control wires and at least a portion ofthe expandable tubular mesh. In some embodiments, the two chord controlwires are advanced further than the main wire to change the angle of therim to a more obtuse angle relative to the longitudinal axis of theinner sheath to facilitate advancement of the inner sheath over thecontrol wires. The expandable tubular mesh and the captured clot orthrombus may be gradually molded to the inner diameter of the innersheath and/or the outer sheath. While very chronic and organizedthrombus may resist deformation and molding, such clots may crumble inthe expandable tubular mesh when withdrawn into the inner sheath and/orthe outer sheath.

In some embodiments, the distal end of the inner and/or outer sheathsmay be flared and/or may be configured to flare to accommodate thetubular mesh and the captured clot or thrombus therein. For example, thesheath(s) may comprise partial depth slits parallel to the longitudinalaxis of the sheath(s) at the distal end of the sheath(s) or the wall ofthe sheath(s) may be gradually thinner toward the distal end to allowexpansion of the sheath diameter.

The distal end of the expandable tubular mesh may be substantiallyclosed and the proximal end of the expandable tubular mesh may be open.The expandable tubular mesh may be made of mylar, nitinol, or some otherresilient and/or expandable material. The length, diameter, and/or poresize of the expandable tubular mesh may vary according to a desiredspecific task or other factors. Such tasks or factors may include theclot burden to be removed, the diameter of the vessel to be treated,etc.

The expandable tubular mesh may have a pore size. For clot removal, thetubular mesh may have a pore size sufficiently large to allow normalblood cells not to be captured and sufficiently small to allow thrombusto be captured. For distal embolic protection, the pore size may besufficiently large to allow normal blood cells not to be captured andsufficiently small to allow atheroemboli as small as 20 microns,frequently as small as 10 microns, to be captured.

The inner sheath may be retractably mounted over the expandable tubularmesh to constrain the tubular mesh in the constrained configuration. Theinner sheath may be distally advanced to engage the proximal end of thetapered tip to circumscribe and constrain the expandable tubular meshand may be proximally retracted to release the expandable tubular meshfrom constraint so that the mesh self-expands into the expandedconfiguration.

The clot extraction catheter may further comprise an inner pusher tubeadvancable within the inner sheath. The inner pusher tube, whenadvanced, may be disposed within the lumen of the inner sheath andin-between the control wires. The pusher tube may comprise a guidewirelumen through which a guidewire can be passed through. The pusher tubemay be used to facilitate advancement of the clot extraction catheterthrough a subject's vasculature to reach a clot. The pusher tube mayfacilitate advancement of the clot extraction catheter through tortuousvasculature. For example, the pusher tube may be used to advance theclot extraction catheter through a femoral artery, through the inferiorvena cava (IVC), and through the right atrium and ventricle of the heartto reach a pulmonary artery. Alternatively or in combination, the clotextraction catheter may be advanced through this tortuous vasculaturewithout the aid of the inner pusher tube. The clot extraction catheterand its component elements such as the inner sheath may be sufficientlyflexible and compliant such that it may navigate through the tortuousvasculature while accommodating for the twists and turns of thevasculature and while minimizing the exertion of any damaging force tothe vessel walls.

In some embodiments, the clot extraction catheter comprises a guidewirechannel. The guidewire channel may be disposed within the expandabletubular mesh and may extend to the tapered tip. The guidewire channelmay have a guidewire lumen configured for a guidewire to be threadedtherethrough. The control wires may be disposed radially over theguidewire channel. The inner and/or outer sheaths may be advancable overthe guidewire channel. In some embodiments, the control wire sheath maybe disposed within the inner sheath. The control wire sheath may houseat least a portion of the control wires, typically the proximalportions.

In some embodiments, the clot extraction catheter further comprises atleast one clot maceration wire disposed over the guidewire channel. Theone clot maceration wire(s) may be manipulated to macerate or breakapart a blood clot. The clot maceration wire may have a self-expandabledistal portion, which may have a tangled or helical configuration. Theclot extraction catheter may further comprise a clot maceration wiresheath advancable over the self-expandable distal portion of themaceration wire(s) to collapse the distal portion. The clot macerationwire sheath may be disposed within the inner sheath.

Aspects of the present disclosure may further provide a system forextracting a clot from a blood vessel. The system may comprise the clotextraction catheter as described herein. The system may further comprisea guidewire advancable within the inner sheath of the clot extractioncatheter. The guidewire may comprise a bulb near a distal end of theguidewire and may also comprise a soft, floppy tip distal to the bulb.The bulb of the guidewire may be used to facilitate retraction of thetubular mesh and/or inner sheath. The distal end of the tapered tipdistal of the tubular mesh may abut the bulb as the guidewire isretracted. Afterwards, further retraction of the guidewire mayadditionally retract the tubular mesh and/or inner sheath. The guidewiremay be used to facilitate the advancement of the clot extractioncatheter through a subject's vasculature to reach a clot. The guidewiremay first be advanced through the vasculature to reach a target locationbefore the clot extraction catheter is advanced over the guidewire. Forexample, the guidewire and/or clot extraction catheter may be introducedinto the vasculature initially through a jugular or femoral vein beforereaching the superior vena cava (SVC) or inferior vena cava (IVC),respectively.

When used as a clot retrieval device, the clot extraction catheterdescribed herein can be used in conjunction with a distal embolicprotection device.

Aspects of the disclosure also provide methods for extracting a clotfrom a bodily vessel or cavity. A distal end of a tapered tip of a clotextraction catheter may be positioned in a lumen of the bodily vessel orcavity proximal of a clot. The tapered tip may be advanced past the clotsuch that a proximal end of the tapered tip is distal of the clot. A rimcoupled to a proximal end of a tubular mesh of the clot extractioncatheter may be opened to open the proximal end of the tubular mesh. Thetubular mesh may be retracted proximally to capture the clot within thetubular mesh. The rim may be closed to close the proximal end of thetubular mesh and enclose the captured clot within the tubular mesh. Theclot extraction catheter may then be removed from the lumen of thebodily vessel or cavity.

An angle of the opened rim relative to a shaft of the clot extractioncatheter may also be adjusted before or during retracting of the tubularmesh to capture the clot. This adjustment may be made by proximally ordistally translating a main control wire of the clot extraction cathetercoupled to the rim independently from proximally or distally translatingat least two chord control wires of the clot extraction catheter.Alternatively or in combination, this adjustment may be made byproximally or distally translating a first chord control wire of the atleast two chord control wires independently from proximally or distallytranslating a second chord control wire of the at least two chordcontrol wires.

The rim coupled to the proximal end of the tubular mesh may be opened toallow the rim to self-expand. To allow the rim to self-expand, an innersheath of the clot extraction catheter may be retracted relative to therim. Alternatively or in combination, the rim may be advanced out of theinner sheath. To close the rim and enclose the captured clot within thetubular mesh, the tubular mesh may be retracted proximally at leastpartially into a lumen of the inner sheath. Alternatively or incombination, the inner sheath may be advanced over the tubular meshenclosing the captured clot. Further, the outer sheath may be used toenclose the tubular mesh with the captured clot (for example, where theinner sheath only partially encloses the tubular mesh with the capturedclot). The outer sheath may be advanced over the tubular mesh with thecaptured clot to fully enclose the tubular mesh before the clotextraction catheter is removed from the bodily vessel or lumen.Alternatively or in combination, the tubular mesh with the captured clotmay be retracted proximally into a lumen of the outer sheath.

To position the distal end of the tapered tip of a clot extractioncatheter in the lumen of the bodily vessel or cavity proximal of a clot,the clot extraction catheter may be distally advanced with a pushertube. Alternatively or in combination, a guidewire may be advancedthrough the bodily vessel or cavity and the clot extraction catheter maybe advanced over the guidewire.

In some embodiments, the method may further comprise a step of expandingan expandable element proximal of the opened rim. Proximally retractingthe tubular mesh to capture the clot with the tubular mesh may also pushthe clot against the expanded expandable element. Alternatively or incombination, the expanded expandable element may be advanced toward theopened rim. To advance the expandable element toward the open rim, theinner sheath, a pusher sheath (further described herein), or a controlwire sheath (further described herein) on which the expandable elementis mounted may be advanced or otherwise translated.

In some embodiments, the method may further comprise a step of expandingat least one clot maceration wire adjacent to the clot. The clot may bemacerated with the clot maceration wire prior to retraction of thetubular mesh to capture the macerated clot. The expanded clot macerationwire may then be collapsed by advancing a clot maceration wire sheathover its expanded portion.

The clot extraction catheter described herein may be used to extract aclot, thrombus, or other materials in a bodily vessel or cavity. Thisbodily vessel or cavity may comprise a blood vessel such as a vein, anartery, the aorta, a pulmonary artery, a vena cava, an inferior venacava (IVC), a superior vena cava (SVC), an internal jugular vein, anexternal jugular vein, a subclavian vein, a hepatic vein, a renal vein,an iliac vein, a common iliac vein, an internal iliac vein, an externaliliac vein, a femoral vein, or a peripheral vein.

In some embodiments, the clot extraction catheter is positioned proximalof the clot by advancing the clot extraction catheter over a guidewire.The clot extraction catheter may comprise a guidewire channel in whichthe guidewire is disposed.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present disclosure will be obtained by reference tothe following detailed description that sets forth illustrativeembodiments, in which the principles of the disclosure are utilized, andthe accompanying drawings of which:

FIG. 1A shows a side view of a clot extraction catheter having itstubular mesh clot capture basket constrained, in accordance with manyembodiments;

FIG. 1B shows a side sectional view of the clot extraction catheter ofFIG. 1A having its tubular mesh clot capture basket constrained;

FIG. 1C shows a side view of the clot extraction catheter of FIG. 1Ahaving its tubular mesh clot capture basket unconstrained;

FIG. 1D shows a side sectional view of the clot extraction catheter ofFIG. 1A having its tubular mesh clot capture basket unconstrained;

FIGS. 2A to 2K show sectional views of the clot extraction catheter ofFIG. 1A in use to remove a clot or thrombus in a blood vessel;

FIG. 3 illustrates a partial cross-section of the dilator tip;

FIG. 4 illustrates the tubular mesh coupled to the dilator tip;

FIG. 5A shows a side view of a clot extraction catheter having itstubular mesh clot capture basket constrained, in accordance with manyembodiments;

FIG. 5B shows a side sectional view of the clot extraction catheter ofFIG. 5B having its tubular mesh clot capture basket constrained;

FIG. 5C shows a side view of the clot extraction catheter of FIG. 5Ahaving its clot capture basket unconstrained;

FIG. 5D shows a side sectional view of the clot extraction catheter ofFIG. 5A having its tubular mesh clot capture basket unconstrained;

FIG. 5E shows a cross-sectional view of the clot extraction catheter ofFIG. 5A taken through line 5E in FIG. 5D;

FIG. 5F shows a schematic of the middle working portion of the clotextraction catheter of FIG. 5A;

FIG. 6A shows a side view of the distal or working end of a clotextraction catheter, in accordance with many embodiments;

FIG. 6B shows a side view of the proximal or handle end of the clotextraction catheter of FIG. 6A;

FIG. 6C shows a perspective view of the distal or working end of theclot extraction catheter of FIG. 6A;

FIG. 6D shows the outer sheath and dilator tip of the clot extractioncatheter of FIG. 6A;

FIG. 7A shows a side view of a clot extraction catheter with anexpandable element, according to many embodiments;

FIG. 7B shows a cross-sectional view of the clot extraction catheter ofFIG. 7A;

FIG. 8A shows a side view of another clot extraction catheter with anexpandable element, according to many embodiments;

FIG. 8B shows a cross-sectional view of the clot extraction catheter ofFIG. 8A;

FIGS. 9A, 9B, 9C, and 9D show a method of use for another clotextraction catheter with an expandable element, according to manyembodiments; and

FIGS. 10A, 10B, 10C, and 10D show sectional side views of a clotextraction catheter having a plurality of clot maceration wires,according to many embodiments.

DETAILED DESCRIPTION

FIGS. 1A to 1D show a clot extraction catheter 100 according to manyembodiments. FIGS. 1A and 1B show the clot extraction catheter 100 withits tubular mesh or clot capture basket 110 in a constrained, deliveryconfiguration. The tubular mesh or clot capture basket 110 may beself-expanding and may comprise a shape-memory material or metal such asNitinol (NiTi). The clot extraction catheter 100 comprises a tubularinner sheath 140 which is advancable over the tubular mesh 110 toconstrain the tubular mesh 110. The tubular inner sheath 140 can beretracted proximally to release the tubular mesh 110 as shown in FIGS.1C and 1D. When unconstrained, the tubular mesh 110 may resilientlyassume its unconstrained configuration which may be in the form of atube sock-like structure. Alternatively or in combination, the tubularmesh 110 may comprise a heat-based shape memory material so that theunconstrained tubular mesh 110 may assume the tube sock-like structurewhen exposed to body temperatures in a bodily vessel or cavity. The clotextraction catheter 100 may further comprise an outer sheath 170 whichmay be advanced over the tubular inner sheath 140 (or the tubular innersheath 140 may be retracted to be within the outer sheath 170). Theouter sheath 170 may have a width or diameter of 8-25 Fr, for example.The inner sheath 140 and/or outer sheath 170 may comprise proximal sidearms (e.g., for the passage of a guidewire, fluid infusion, etc.) and/orinjection ports. The inner sheath 140 and/or outer sheath 170 may alsobe provided with one or more radiopaque markers to facilitate locatingthe inner sheath 140 and/or outer sheath 170 as they are advancedthrough the vasculature.

The clot extraction catheter 100 may further comprise an atraumatic,dilator tip 120. The dilator tip 120 may be elongate in shape andtapered with a straight surface to facilitate the passage of the tip 120through a clot without pushing the clot. The dilator tip has a distalend 122 and a proximal end 124. The proximal end 124 may be rounded sothat the dilator tip 120 is atraumatic when proximally retracted. Thewidth or diameter of the dilator tip 120 at the proximal end 124 may beslightly greater than the width or diameter of the tubular inner sheath140. The distal end 142 of the tubular inner sheath 140 may abut theproximal end 124 of the dilator tip 120 when distally advanced. Theproximal end 124 of the dilator tip 120 may be attached or fixed to adistal portion 112 of the tubular mesh 110. The outer sheath 170 mayhave a width or diameter such that it may be advanced over the dilatortip 120. In some embodiments, the outermost diameter of the dilator tip120 may match the innermost diameter of the distal end of the outersheath 170 such that the dilator tip 120 may be fitted to the distal endof the outer sheath 170 when retracted. Alternatively or in combination,the distal end of the outer sheath 170 may be flared.

The distal portion 112 of the tubular mesh 110 may be tapered. Thistapering may end at the distal end 116 of the tubular mesh 110. Thedistal end 116 of the tubular mesh 110 may be coupled to the dilator tip130. The distal end 122 of the dilator tip 120 may be coupled to thedistal end 116 of the tubular mesh 110 as well. A guidewire 160 may bepassed through the lumen of the inner sheath 140 and disposed in-betweenthe control wires 132, 134 a, 134 b. The guidewire 160 may have adiameter of 0.025 inches, for example. The guidewire 160 may comprise abullet or bulb 162 near the distal end of the guidewire 160. The bulletor bulb 162 may have a width or diameter greater than that of the distalend 122 of the dilator tip 120 such that distal advancement of the clotextraction catheter 100 may be limited. The clot extraction catheter 100may be distally advanced until the distal end 122 of the dilator tip 120abuts the bullet or bulb 162. The bullet or bulb 162 may have a diameterof 0.035 inches, for example. The bullet or bulb 162 may also facilitatein the navigation of the guidewire 160 through tortuous vasculature aswell facilitate advancement of the guidewire 160 through clot, thrombus,emboli, or the like in a bodily vessel or lumen.

The open proximal end 114 of the tubular mesh 110 may be coupled to arim or ring 130. The rim or ring 130 may be self-expanding. Whenunconstrained by the inner sheath 140, the rim or ring 130 mayresiliently expand to facilitate the opening and expansion of thetubular mesh 110. The rim or ring 130 may comprise a shape-memorymaterial such as Nitinol (NiTi) to facilitate self-expansion. Theshape-memory material may be heat-based, for example, so that the rim orring 130 may assume its expanded configuration when exposed to bodilytemperatures in a bodily vessel or cavity.

At least three control wires 132, 134 a, 134 b may be coupled to the rimor ring 130. The control wires may comprise a main control wire 132 andtwo chord wires 134 a, 134 b. The control wires 132, 134 a, 134 b may bedisposed within the inner sheath 140 and run the length of the clotextraction catheter 100 proximally from the rim or ring 130. The controlwires 132, 134 a, 134 b may be independently manipulated at a proximal,handle end of the clot extraction catheter 100. The main control wire132 may be translated either distally or proximally independently fromthe distal or proximal translation of the two chord wires 134 a, 134 b.In some embodiments, each of the chord wires 134 a, 134 b may beindependently translated from each other as well. The control wires 132,134 a, 134 b may be manipulated to change the angle of the expanded rim130 relative to the longitudinal axis of the inner sheath 140. Theattachment points of the control wires 132, 134 a, 134 b may be evenlydistributed over the circumference of the rim 130. The control wires132, 134 a, 134 b may have a width of 0.010 inches, for example. In someembodiments, the chord wires 134 a, 134 b may be thinner than the mainwire 132. In alternative embodiments, two or more of the control wires132, 134 a, 134 b may be attached to one another at proximal portionsthereof such that they may be user manipulated in conjunction. Also,while three control wires are shown in FIGS. 1A to 1D, alternativenumber of control wires (such as one, two, or four or more) may beprovided instead.

FIGS. 2A to 2K show the clot extraction catheter 100 in use to capture aclot CL in the lumen BVL of a blood vessel BV. The blood vessel BV maybe selected from the group comprising a vein, an artery, a pulmonaryartery, a vena cava, an inferior vena cava (IVC), a superior vena cava(SVC), an internal jugular vein, an external jugular vein, a subclavianvein, a hepatic vein, a renal vein, an iliac vein, a common iliac vein,an internal iliac vein, an external iliac vein, a femoral vein, aperipheral vein, and a peripheral artery, for example. The clotextraction catheter 100 may also be used to capture other solid,biological material in other bodily vessels or cavities such as theureter, urethra, renal pelvis, bladder, intestines, esophagus, stomach,small intestines, large intestines, colon, vagina, uterus, trachea, andbronchus, to name a few.

As shown in FIG. 2A, a blood vessel lumen BVL may have a clot CL lodgedtherein. In some embodiments, a diagnostic catheter and guidewire may bepassed through the clot CL, followed by an exchange of the diagnosticcatheter with the guidewire 160 as shown in FIG. 2B. In someembodiments, an angioplasty catheter may be advanced through clot CLeither through the diagnostic catheter or the guidewire 160 and the clotCL may be expanded to facilitate the later advancement of the clotextraction catheter 100 therethrough.

As shown in FIG. 2B, the guidewire 160 and bulb 162 may be advancedthrough the clot CL. The clot extraction catheter 100 may be advancedover the guidewire 160 to be positioned just proximally of the clot CL.At this point, most of the elements of the clot extraction catheter 100remain housed within the outer sheath 170. The tapered, dilator tip 120may be exposed.

As shown in FIG. 2C, the clot extraction catheter 100 may be advancedthrough the clot CL. In particular, the inner sheath 140 and the dilatortip 120 may be advanced from the outer sheath 170 through the clot CL.The inner sheath 140 and the dilator tip 120 may be advanced through theclot CL until the distal end 122 of the dilator tip 120 abuts the bulb162 of the guidewire 160.

As shown in FIG. 2D, the inner sheath 140 may now be retractedproximally and/or the tubular mesh 100 and the self-expanding rim orring 130 advanced distally so that the tubular mesh 110 and theself-expanding rim or ring 130 are unconstrained and expanded justdistal of the clot CL. The tubular mesh 110 of the clot extractioncatheter may be telescoped up to itself to shorten the mesh 100 beyondthe clot, e.g., by advancing the tapered tip 120 to the bulb 162 andpushing the rim 130 forward toward the bulb 162. The guidewire 160 withthe bulb 162 may also be pulled proximally to pull the dilator tip 120proximally to facilitate the telescoping and shortening of the tubularmesh 110.

As shown in FIG. 2E, the inner sheath 140 may instead be retractedproximally and/or the tubular mesh 110 and the self-expanding rim orring 130 advanced distally so that the tubular mesh 110 and theself-expanding rim or ring 130 are unconstrained and expanded withlittle or no telescoping. The expanded tubular mesh 110 and rim/ring 130may be positioned immediately distal of the clot CL.

As shown in FIGS. 2F and 2G, the expanded tubular mesh 110 may beproximally retracted partially as shown in FIG. 2F and then completelyas shown in FIG. 2G to capture the clot CL within the tubular mesh 110.The tubular mesh 110 may proximally retracted by proximally retractingone or more of the main control wire 132, or the two chord wires 134 a,134 b. As the expanded tubular mesh 110 is retracted, the tubular mesh110 may expand at least axially to accommodate any captured clot CL.

As shown in FIGS. 2H and 2I, the angle of the rim 130 relative to thelongitudinal axes of the inner sheath 140 and/or outer sheath 170 may becontrolled to facilitate capture of the clot CL or the retraction of thetubular mesh 110 and the rim 130 first constrained by the distal portionof the inner sheath 140 and back within the outer sheath 170. The rim130 angle may be initially be 0° as shown in FIGS. 2E to 2G but may bemanipulated to be 45° as shown in FIG. 2H. This angle may be controlledby manipulating one or more of the control wires 132, 134 a, or 134 b.As shown in FIG. 2H, the two chord control wires 134 a, 134 b may beadvanced distally and/or the main control wire 132 may be retractedproximally to control the angle. By providing three or more controlwires, the rim 130 angle may be controlled with two or more degrees offreedom. Alternatively or in combination, the clot extraction catheter100 may be rotated to control the orientation of the rim 130 and thetubular mesh 110. In other embodiments, the control wires 132, 134 a,134 b may have a fixed orientation relative to one another such that therim 130 angle may be fixed (such as to 45°, for example.)

As shown in FIG. 2I, the rim and the tubular mesh 110, including theclot CL captured therein, may be proximally retracted partially into theinner sheath 140 (i.e., the proximal portion of the tubular mesh 110 maybe retracted into and constrained by the inner sheath 140). This maypartially or completely close the rim 130 and the mesh 110. In someembodiments, the distal end of the inner sheath 140 may be flared and/ormay become flared as the tubular mesh 110 and the captured clot CL areretracted to facilitate such retraction.

As shown in FIG. 2J, as the captured clot CL is retracted into the outersheath 170, the outer sheath 170 may change the shape of the clot CL andmay break apart or cause the crumbling of the larger particles of theclot CL. The captured clot CL, the tubular mesh 110, and the innersheath 140 may be fully retracted into the outer sheath such that theclot extraction catheter assumes the configuration shown by FIG. 2B.

As shown in FIG. 2K, the clot extraction catheter 100 and the guidewire160 may then be removed from the blood vessel BV to leave the bloodvessel lumen BVL free and clear of any clot. In some cases, the clotextraction catheter 100 is retracted before the guidewire 160 isretracted. The guidewire 160 can be left in place to facilitate bloodvessel access and optionally further treatment or intervention. Iffurther clot extraction may be necessary, the guidewire 160 and theouter sheath 170 may both be left in place and only the inner sheath 140and clot extraction catheter 100 with the captured clot CL removed. Theamount of clot removed can be ascertained by introducing a diagnosticcatheter over the guidewire 160 and contrast angiography performed overthe wire. The clot extraction catheter and the inner sheath 140 may becleaned and reinserted into the outer sheath 170, or a new differentsized clot extractor 100 and its inner sheath 140 may be introduced.

FIG. 3 illustrates an exemplary embodiment of the dilator tip 120positioned adjacent the inner sheath 140. The dilator tip 120 and theinner sheath 120 may be any of the embodiments disclosed in thisspecification. The dilator tip 120 includes a conical tapered outersurface 304, a distal guidewire port 306, guidewire lumen 320 and aproximal end that cooperates with the distal end of the inner sheath140. The proximal end of the dilator tip 120 includes smooth radiusouter edge 310 to minimize vascular trauma during retraction of thedilator tip 120. Flat shoulder 312 provides a stop against which thedistal end of inner sheath 140 may rest. Also, a flat proximal end 316facilitates self-centering of the inner sheath 140 when engaged with theproximal end of the dilator tip 120 Inner edges 314, 318 also have radiiin order to prevent vascular trauma and provide a smooth, self-centeringtransition so that inner sheath 140 is easily advanced and aligned withthe proximal end of the dilator tip 120.

FIG. 4 illustrates the tubular mesh 110 disposed in the dilator tip 120.The tubular mesh and the dilator tip may be any of the embodimentsdisclosed herein. The tubular mesh 110 preferably has a width 404adjacent the proximal end of dilator tip 120 that is less than the widthof the flat proximal end 316. This minimizes the possibility of thetubular mesh 110 being trapped or caught by the distal end of innersheath 140 (not illustrated).

As shown in FIGS. 5A-5E, the clot extraction catheter 100 may furthercomprise a guidewire channel 150. FIG. 5A shows a side view of the clotextraction catheter 100. FIG. 5B shows a side sectional view of the clotextraction catheter 100 having its tubular mesh clot capture basket 110constrained. FIG. 5C shows a side view of the clot extraction catheter100 having its clot capture basket 110 unconstrained. FIG. 5D shows aside sectional view of the clot extraction catheter 100 having itstubular mesh clot capture basket 110 unconstrained. FIG. 5E shows across-sectional view of the clot extraction catheter of FIG. 5A takenthrough line 5E in FIG. 5D. FIG. 5F shows a schematic of the middleworking portion of the clot extraction catheter 100, including the rimor ring 130 of the tubular mesh clot capture basket 110 and the controlwires 132, 134 a, and 134 b attached thereto.

As shown in FIGS. 5B-5F, the guidewire channel 150 may be disposedwithin the lumens of both the inner sheath 140 and the outer sheath 170.The control wires 132, 134 a, and 134 b may also be disposedcircumferentially over the guidewire channel 150. The guidewire channel150 may extend from the proximal end or portion of the clot extractioncatheter 100 to the distal end 122 of the dilator tip 120.

As shown in FIGS. 5E and 5F, the control wires 132, 134 a, and 134 b maybe housed within a control wire sheath 135 that may be retracted withinthe inner sheath 140. The proximal portions of the chord control wires134 a and 134 b may be coupled together to a single control wire 134 cwhich may be actuated in combination with the main control wire 132 tochange the pitch or angle of the rim or ring 130 relative to thelongitudinal axis of the clot extraction catheter 100. The longitudinalaxis of the clot extraction catheter 100 may, for example, be coaxialwith one or more of the guidewire 160, the control wire sheath 135, theinner sheath 140, or the outer sheath 170.

FIG. 6A shows a side view of the distal or working end 100 a of the clotextraction catheter 100. The distal or working end 100 a of the clotextraction catheter 100 may include the dilator tip 120, the tubularmesh clot capture basket 110, the rim or ring 130, the guidewire channel150, the control wire sheath 135, and the control wires 132, 134 a, and134 b. The distal or working end 100 a may be retracted within the innersheath 140. As shown in FIG. 6A, the distal or working end 100 a isextended from the inner sheath 140 such that the clot capture basket 110is in its expanded, unconstrained configuration. The distal or workingend 100 a may be extended out a distance of 150 mm from the distal end122 of the dilator tip 120 and the distal end of the inner sheath 140,for example. As discussed above, one or more radiopaque markers may beprovided such as on the inner sheath 140 and/or the dilator tip 120 tohelp the user determine the relative positioning of the differentcomponents of the clot extraction catheter 100. FIG. 6C shows aperspective view of the distal or working end 100 a of the clotextraction catheter 100.

FIG. 6B shows a side view of the proximal or handle end 100 b of theclot extraction catheter 100. At the proximal or handle end 100 b, theproximal end of the inner sheath 140 may be coupled to a hub 172. Thehub 172 may be coupled to a suction channel 174 which may providesuction to the lumen of the inner sheath 140. The suction provided bythe suction channel 174 may facilitate the removal and retraction ofclot captured by the basket 110 when retracted back into the innersheath 140. The control wire sheath 135 may lead from the hub 172 to ahandle 101. The handle 101 may comprise a button or control 101 b, sucha slider, which may be actuated by the user to control the control wires132, 134 a, and 134 b housed within the control wire sheath 135 toadjust the pitch or angle of the rim or ring 130. The handle 101 maycomprise an inner lumen such that the guidewire 160 may be threadedthrough one or more (typically each of) the handle 101, the control wiresheath 135, the hub 172, and the inner sheath 140, for example, througha guidewire channel 150. As discussed above and shown in FIG. 6D, anintroduction dilator tip 180 may be threaded through an outer sheath 170to facilitate advancement and positioning of the outer sheath 170 andsubsequently the clot extraction catheter 100 through tortuousvasculature to be adjacent a clot to be captured.

In some embodiments, an expandable element may be provided to facilitateclot capture in conjunction with the self-expanding rim. The expandableelement may typically comprise an inflatable balloon inflatable throughan inflation lumen. As the expanded rim or ring 130 is retracted, theclot CL may be pushed against the expanded expandable element to helpurge the clot CL into the tubular mesh and prevent clot material fromdiverting into undesired locations. Alternatively or in combination, theexpanded expandable element may be translated to fulfill this function.

FIG. 7A shows a side view of a clot extraction catheter 100 with anexpandable element 191. The expandable element 191 may be mounted on thedistal end of a pusher or balloon sheath or shaft 195. As shown in FIG.7B, the pusher sheath 195 may be disposed radially in-between the inner,control wire sheath 135 and the inner sheath 140. The pusher sheath 195may include an inflation lumen to inflate or deflate the expandableelement 191.

FIGS. 8A and 8B show side and sectional views, respectively, of anotherclot extraction catheter 100 having an expandable element 191. Theexpandable element 191 may be mounted on the distal portion of the innersheath 140, which may also provide an inflation lumen 193 for theexpandable element 191.

FIGS. 9A, 9B, 9C, and 9D show side views of another clot extractioncatheter 100 having an expandable element 191. The expandable element191 may be mounted within the inner sheath 140 and on the control wiresheath 150. The control wires 134 a, 134 b, and 132 surround theexpandable element 191.

FIG. 9A shows the expandable ring 130 expanded distally of the clot CL.The expanded expandable element 191 mounted on the control wire sheath150 is positioned proximally of the clot CL.

FIG. 9B shows the expandable element 191 being expanded. When expanded,the expandable element 191 may urge the control wires 132, 134 a, and134 b laterally outward. To minimize the pushing of the control wires132, 134 a, and 134 b against the blood vessel inner wall and possiblycausing tissue damage, the maximum size, shape, and/or other parametersof the expandable element 191 may be limited.

FIG. 9C shows the expanded ring 130 and the expanded expandable element191 may be urged toward one another to urge the clot CL into the tubularmesh 110. Once the clot CL is fully captured, the expandable element 191may be collapsed and the tubular mesh 110, including the captured clotCL, may be retracted into the inner sheath 140 and/or the outer sheath170.

In some embodiments, expandable wire(s) may be provided to facilitateclot capture in conjunction with the self-expanding rim. Theseexpandable wire(s) may be actuated to macerate or break apart clot tofacilitate their capture in the tubular mesh 110 or the inner lumen ofthe inner sheath 140. The use of such expandable wire(s) may be combinedwith the use of the expandable element described above to facilitateclot capture.

FIGS. 10A-10D show a clot extraction catheter 100 having a plurality ofmaceration wires 197. The plurality of wires 197 may be coaxial with theguidewire channel 150 and may be disposed over the guidewire channel150. When the clot extraction catheter 100 is positioned at a targetsite, the tubular mesh 110 and the self-expanding rim 130 may beadvanced distally of the plurality of wires 197 and the clot CL.

The plurality of wires 197 may be collapsed and housed within amaceration wire sheath 197 as shown in FIGS. 10A and 10C. The macerationwire sheath 197 may be housed within the inner sheath 140. The pluralityof maceration wires 197 may have a self-expandable, distal portion. Asshown in FIGS. 10A and 10B, the wires 197 may be tangled (randomly, forexample) at its distal portion. As shown in FIGS. 10C and 10D, the wires197 may be helically wound at its distal portion. The wires 197 may bemade of a shape memory material and/or metal such as Nitinol so as to bebiased to expand to assume the tangled (FIG. 10B) or spiral or helical(FIG. 10D) configurations. The maceration wire sheath 197 may beretracted to expose the distal portion as shown in FIGS. 10B and 10D.Typically, the distal portion is expanded at the site of the clot CL.Once expanded, the wires 197 may be rotated and/or translated tomacerate or break apart the clot CL. The wires 197 can then be collapsedby advancing the maceration wire sheath 197 thereover. Subsequently, thebroken apart clot may be captured by the tubular mesh 110 and the lumenof the inner sheath 140 as described above.

While preferred embodiments of the present disclosure have been shownand described herein, it will be obvious to those skilled in the artthat such embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the scope of the disclosure. It shouldbe understood that various alternatives to the embodiments of thedisclosure described herein may be employed in practicing the invention.It is intended that the following claims define the scope of theinvention and that methods and structures within the scope of theseclaims and their equivalents be covered thereby.

1. A clot extraction catheter comprising: an expandable tubular meshhaving a distal end and a proximal end, the tubular mesh having anexpanded configuration and a constrained configuration; a tapered tipfixed to the distal end of the expandable tubular mesh; a guidewirechannel disposed within the expandable tubular mesh and extending to thetapered tip, the guidewire channel having a guidewire lumen configuredfor a guidewire to be threaded therethrough; a self-expanding rimattached to the proximal end of the expandable tubular mesh, theself-expanding rim having an unconstrained diameter which is greaterthan a width of the proximal end of the tapered tip; at least threecontrol wires attached to the self-expanding rim and disposed radiallyover the guidewire channel; an inner sheath advancable over the at leastthree control wires and guidewire channel to constrain at least aportion of the self-expanding rim and at least a portion of the tubularmesh within a lumen of the inner sheath, wherein the at least threecontrol wires can be manipulated to control the angle of theself-expanding rim relative to an axis of the inner sheath when theself-expanding rim is unconstrained, wherein the at least three controlwires comprises a main wire translatable proximally and distally and twochord wires translatable proximally and distally independently from themain wire to control the angle of the self-expanding rim relative to theaxis of the shaft when the self-expanding rim is unconstrained.
 2. Theclot extraction catheter as in claim 1, further comprising an outersheath advancable over the inner sheath and the guidewire channel. 3.The clot extraction catheter as in claim 2, further comprising anexpandable element.
 4. The clot extraction catheter as in claim 3,wherein the expandable element is mounted on a distal end of the outersheath.
 5. The clot extraction catheter as in claim 3, wherein theexpandable element comprises an inflatable balloon.
 6. The clotextraction catheter as in claim 3, wherein the expandable element ismounted on a pusher sheath being translatable relative to one or more ofthe inner or outer sheaths.
 7. The clot extraction catheter as in claim6, wherein the pusher sheath is disposed within the outer sheath.
 8. Theclot extraction catheter as in claim 7, wherein the pusher sheath isdisposed within the inner sheath.
 9. The clot extraction catheter as inclaim 1, wherein the proximal end of the tapered tip has a rounded lipto reduce interference as the catheter is one or more of advanceddistally or retracted proximally through a bodily lumen or cavity. 10.(canceled)
 11. The clot extraction catheter as in claim 1, wherein thetwo chord wires comprises a first chord wire and a second chord wireeach independently translatable proximally and distally to control theangle of the self-expanding rim relative to the axis of the sheath whenthe self-expanding rim is unconstrained.
 12. The clot extractioncatheter as in claim 1, wherein the proximal ends of the two chord wiresare coupled together to form a control wire complementary to the maincontrol wire.
 13. The clot extraction catheter as in claim 1, whereinthe distal end of the expandable tubular mesh is open to allow theguidewire to be passed therethrough.
 14. The clot extraction catheter asin claim 1, wherein the proximal end of the expandable tubular mesh isopen.
 15. The clot extraction catheter as in claim 1, wherein the innersheath is retractably mounted over the expandable tubular mesh toconstrain the tubular mesh in the constrained configuration, and whereinthe inner sheath may be distally advanced to engage the proximal end ofthe tapered tip to circumscribe and constrain the expandable tubularmesh and may be proximally retracted to release the expandable tubularmesh from constraint so that the mesh self-expands into the expandedconfiguration.
 16. The clot extraction catheter as in claim 1, furthercomprising a control wire sheath disposed within the inner sheath andhousing at least a portion of the at least three control wires.
 18. Theclot extraction catheter as in claim 1, further comprising at least oneclot maceration wire disposed over the guidewire channel, the at leastone clot maceration wire being manipulable to macerate clot.
 19. Theclot extraction catheter as in claim 18, wherein the clot macerationwire has a self-expandable distal portion.
 20. The clot extractioncatheter as in claim 19, wherein the self-expandable distal portion hasa tangled or helical configuration.
 21. The clot extraction catheter asin claim 19, further comprising a clot maceration wire sheath advancableover the self-expandable distal portion of the at least one clotmaceration wire to collapse the distal portion, wherein the clotmaceration wire sheath is disposed within the inner sheath.
 22. A systemfor extracting a clot from a blood vessel, the system comprising: theclot extraction catheter as in claim 1; and a guidewire advancablewithin the guidewire channel of the clot extraction catheter.
 23. Asystem as in claim 22, wherein the guidewire comprises a bulb near adistal end of the guidewire.
 24. The system of claim 23, wherein theguidewire comprises a soft, floppy tip distal to the bulb.
 25. A methodfor extracting a clot from a bodily vessel or cavity, the methodcomprising: advancing a clot extraction catheter over a guidewire toposition a distal end of a tapered tip of the clot extraction catheterin a lumen of the bodily vessel or cavity proximal of a clot, theguidewire being disposed within a guidewire channel of the clotextraction catheter; advancing the tapered tip past the clot such that aproximal end of the tapered tip is distal of the clot; opening a rimcoupled to a proximal end of a tubular mesh of the clot extractioncatheter to open the proximal end of the tubular mesh; retracting thetubular mesh proximally to capture the clot within the tubular mesh;closing the rim to close the proximal end of the tubular mesh andenclose the captured clot within the tubular mesh; removing the clotextraction catheter from the lumen of the bodily vessel or cavity; andadjusting an angle of the opened rim relative to a sheath of the clotextraction catheter before or during retracting of the tubular mesh tocapture the clot, wherein adjusting the angle comprises proximally ordistally translating a main control wire of the clot extraction cathetercoupled to the rim independently from proximally or distally translatingat least two chord control wires of the clot extraction catheter. 26.(canceled)
 27. (canceled)
 28. The method for extracting a clot as inclaim 25, wherein adjusting the angle comprises proximally or distallytranslating a first chord control wire of the at least two chord controlwires independently from proximally or distally translating a secondchord control wire of the at least two chord control wires.
 29. Themethod for extracting a clot as in claim 25, wherein opening the rimcoupled to the proximal end of the tubular mesh comprises allowing therim to self-expand.
 30. The method for extracting a clot as in claim 25,wherein opening the rim coupled to the proximal end of the tubular meshcomprises one or more of retracting an inner sheath of the clotextraction catheter over the rim or advancing the rim through the innersheath of the clot extraction catheter.
 31. The method for extracting aclot as in claim 25, wherein closing the rim to close the proximal endof the tubular mesh and enclose the captured clot within the tubularmesh comprises one or more of retracting the tubular mesh proximally atleast partially into a lumen of an inner sheath of the clot extractioncatheter or advancing the inner sheath over the tubular mesh.
 32. Themethod for extracting a clot as in claim 31, wherein closing the rim toclose the proximal end of the tubular mesh and enclose the captured clotwithin the tubular mesh comprises one or more of advancing an outersheath over the inner sheath and the tubular mesh having the capturedclot therein or retracting the inner sheath and the tubular mesh havingthe captured clot therein proximally into a lumen of the outer sheath.33. The method for extracting a clot as in claim 25, wherein positioningthe distal end of the tapered tip of a clot extraction catheter in thelumen of the bodily vessel or cavity proximal of a clot comprisesdistally advancing the clot extraction catheter with a pusher tube. 34.The method for extracting a clot as in claim 25, wherein positioning thedistal end of the tapered tip of a clot extraction catheter in the lumenof the bodily vessel or cavity proximal of a clot comprises advancingthe guidewire through the bodily vessel or cavity.
 35. The method forextracting a clot as in claim 25, further comprising expanding anexpandable element proximal of the opened rim.
 36. The method forextracting a clot as in claim 35, wherein retracting the tubular meshproximally to capture the clot within the tubular mesh comprises pushingthe clot against the expanded expandable element.
 37. The method forextracting a clot as in claim 36, wherein pushing the clot against theexpanded expandable element comprises advancing the expandable elementtoward the opened rim.
 38. The method for extracting a clot as in claim37, wherein advancing the expandable element toward the open rimcomprises translating an inner sheath, a pusher sheath, or a controlwire sheath the expandable element is mounted on.
 39. The method forextracting a clot as in claim 25, further comprising expanding at leastone clot maceration wire adjacent to the clot.
 40. The method forextracting a clot as in claim 39, further comprising macerating the clotwith the expanded at least one clot maceration wire prior to retractingthe tubular mesh proximally to capture the clot within the tubular mesh.41. The method for extracting a clot as in claim 39, further comprisingadvancing a clot maceration wire sheath over an expanded portion of theexpanded at least one clot maceration wire to collapse the expanded atleast one clot maceration wire.
 42. The method for extracting a clot asin claim 25, wherein the bodily vessel or cavity comprises a bloodvessel.
 43. The method for extracting a clot as in claim 39, wherein theblood vessel is selected from the group comprising a vein, an artery,the aorta, a pulmonary artery, a vena cava, an inferior vena cava (IVC),a superior vena cava (SVC), an internal jugular vein, an externaljugular vein, a subclavian vein, a hepatic vein, a renal vein, an iliacvein, a common iliac vein, an internal iliac vein, an external iliacvein, a femoral vein, and a peripheral vein.